1. Field of the Invention
The present invention relates to a conveyance system.
2. Description of the Related Art
As a conventional conveyance system, a conveyance system described in Japanese Patent Application Laid-Open Publication No. 2002-179203, for example, is known. The conveyance system described in Japanese Patent Application Laid-Open Publication No. 2002-179203 includes a carrier that conveys a cassette on which an ID tag is attached, the carrier equipped with an ID reader that identifies the ID tag, and a station on which the cassette is placed, and the conveyance system controls conveyance of the cassette on the basis of the ID tag attached on the cassette.
As in the conveyance system described above in Japanese Patent Application Laid-Open Publication No. 2002-179203, controlling the cassette on the basis of the ID tag is effective from the viewpoint of accuracy and efficiency of conveyance. In recent years, faster processing in manufacturing semiconductor devices has been promoted, and shortening of a takeout time in a semiconductor manufacturing device has been required. At the same time, further speeding up of the time for conveying semiconductor wafers between processes has been required. In addition, recent upsizing of semiconductor wafers has increased the size of a front opening unified pod (FOUP, also referred to as a cassette) as a container that accommodates the semiconductor wafers. Accordingly, in a semiconductor manufacturing plant, more space is required for accommodating the FOUP than ever before, but securing space for accommodating the FOUP within a limited space is not easy.